Abstract: A ceramic substrate for densely integrated semiconductor arrays which is superior in a coefficient of thermal expansion, dielectric constant, strength of metallized bond, and mechanical strength, comprising a sintered body composed essentially of mullite crystals and a non-crystralline binder composed of SiO.sub.2, Al.sub.2 O.sub.3, and MgO, is provided.

Abstract: The rotating mirror light deflecting system employs a non-circular dynamic gas bearing providing dynamic pressure to radially support the shaft. The bearing is provided internally with a multiplicity of grooves or embankments whereby dynamic gas pressure is increased to enhance rigidity. The bearing radially moves as a whole with damping according to a movement of the shaft, thus permitting nondestructive movement of the shaft and absorption of the resonant energy of the shaft. The shaft and the bearing will not come in contact with each other, and oscillation energy of the shaft is absorbed or dissipated by an external viscous or hysteresis resistance of the bearing therefore resonance oscillation is attenuated on the instant it occurs.

Abstract: A ceramic substrate for densely integrated semiconductor arrays which is superior in a coefficient of thermal expansion, dielectric constant, strength of metallized bond, and mechanical strength, comprising a sintered body composed essentially of mullite crystals and a non-crystalline binder composed of SiO.sub.2, Al.sub.2 O.sub.3, and MgO, is provided.

Abstract: Ceramic insulating substrate layers (1) for a multilayered ceramic wiring circuit board (3) consist essentially of crystals of mullite and sillimanite, non-crystalline silicon dioxide occupying the interstices between the crystals and magnesium oxide dissolved substantially in the crystals in solid solution and have a thermal expansion coefficient of 40-60.times.10.sup.-7 /.degree. C. and a dielectric constant below 6.7.

Abstract: A ceramic wiring substrate and a process for producing the same having a conductive layer, obtained by sintering a conductive paste comprising 85 to 97% by weight of a tungsten powder and 15 to 3% by weight of a sintering additive (for conductive metal) having a specified composition, on a mullite ceramic substrate.

Abstract: A ceramic wiring board comprising a silica board having pores of several ten to several hundred .ANG. in diameter amounting to 5 to 20 vol % of the insulating layer, and a process for producing the same, which comprises heat-treating a silicon alkoxide to form a fine silica powder and sintering the fine powder. This board has good mechanical characteristics and a high signal propagation speed.

Abstract: A ceramic multilayer wiring board is provided in which ceramic insulating layers and wiring patterns provided thereon are connected by conductors filling through-holes formed in the ceramic insulating layers. The through-holes are so formed that the superficial portions of each through-hole of the ceramic multilayer wiring board is smaller in diameter than the inside portion of the through-hole between the superficial portion. This can prevent the board from being cracked around the through-holes.

Abstract: An electroconductive molybdenum paste comprising 100 parts by weight of a mixture consisting of 68.0 to 89.2% by weight of molybdenum powders having an average particle size of 0.5 to 10 .mu.m, 10.0 to 27.0% by weight of a solvent, and 0.8 to 5.0% by weight of a binder, 0.5 to 5.0 parts by weight of a gelling agent, and 0.5 to 4.0 parts by weight of a silane coupling agent can firmly fill throughholes of a green sheet without formation of clearances and hollows in the resulting conductors in the throughholes, with better surface roughness of the conductor surfaces in the throughholes, and without development of cracks near the throughholes.

Abstract: A ceramic wiring board which comprises ceramic part in which through-holes are made, sintered wiring pattern part provided on the surface of said ceramic part and sintered conductor part filled in said through-holes shows much decrease in cracks at the through-hole part caused by sintering and remarkable reduction in moisture absorbency when the ceramic part comprises ceramic containing a sintering assistant and the sintered conductor part comprises a metal containing the same sintering assistant as that present in said ceramic part.

Abstract: A ceramic multilayer circuit board is provided by sintering a multilayer wiring substrate containing alumina as a main component, which was prepared by the green sheet process, nickel plating and gold plating in this order on the superficial wiring conductor layer, printing a thick film conductor paste on the gold plating layer, firing the printed substrate and finally printing a thick film resistor paste on at least part of the thick film conductor layer and firing to form a thick film resistor layer.

Abstract: A wiring circuit board with a fine wiring pattern free from disconnection and poor insulation is produced by forming an insulating layer consisting of at least two insulating substances having different dissociation energies for metalization, including metal elements, on a substrate and irradiating the insulating layer with an energizing beam by scanning, thereby forming a wiring pattern as desired.

Abstract: A method for producing an optical fiber comprises (i) the step of depositing a barrier layer on the inner wall surface of a glass tube by the CVD (chemical vapor deposition) process, said barrier layer being capable of preventing the diffusion of impurities and being made of high-silica glass which has a refractive index that is substantially equal to that of the glass tube and which contains at least one substance for lowering the refractive index of silica and at least one substance for raising the refractive index of silica, (ii) the step of depositing a glass film of desired refractive index on the barrier layer by the CVD process, (iii) the step of heating and collapsing the resultant glass tube into a composite rod or the so-called optical fiber preform, and (iv) the step of heating and drawing said optical fiber preform into the optical fiber, whereby the optical fiber which has the impurity diffusion-preventing layer between the core and the outside glass layer can be easily produced.

Abstract: A method of producing an optical fiber comprising (i) the step of depositing a glass film of desired refractive index onto the inner wall surface of a quartz tube by the CVD (chemical vapor deposition) process, (ii) the step of heating the quartz tube to a high temperature while the gas of a compound which forms an oxide, enhancing the refractive index of the glass film, in an oxidizing atmosphere at the high temperature is kept flowing into the quartz tube along with an oxidizing gas, (iii) the step of heating and collapsing the quartz tube into a solid rod or the so-called preform, and (iv) the step of heating and drawing the optical fiber preform into the optical fiber.In the optical fiber produced by this method of manufacture, the lowering of the refractive index of the central part of the optical fiber is sharply reduced.

Abstract: A pulse generator comprising an induction element, and a nonlinear condenser whose dielectric material portion is made of ferroelectric ceramics represented by a general formula of (Pb.sub.1-x-y, Ba.sub.x, Sr.sub.y)(Ti.sub.z, Zr.sub.1-z)O.sub.3.

Abstract: For drawing an optical fiber from an optical fiber preform there are provided means for heating an optical fiber preform, means for pulling out an optical fiber from the optical fiber preform whose fore end part has been fused by heating, and means for causing gas to flow along the outer peripheral surface of the fused part of the optical fiber preform. By further controlling the flow rate of the gas and/or the pulling-out velocity for the optical fiber according to fluctuations in the fiber diameter of the optical fiber, an optical fiber of uniform fiber diameter is easily provided.

Abstract: There is provided a method of producing a ceramic represented by the general formula of ABO.sub.3, wherein A includes Pb and at least one element selected from the group consisting of Ba and Sr and B is either of Zr or both of Zr and Ti, by hot-pressing a complex oxide obtained by calcining the mixture of the oxides of A and B characterized by that a solid solution of the oxides of Ba and/or Sr and the oxide of the element constituting B, such as BaTiO.sub.3, SrZrO.sub.3 or (Ba, Sr)ZrO.sub.3, is used as the starting oxides of Ba and/or Sr, and that the starting material contains PbO in an amount of 3 - 20 mol% in excess of that calculated for the objective composition of the final product. Ceramics produced by the method of the present invention have ferroelectric properties and are optically transparent.