Abstract: New black color insulator thin films comprising Pr oxide, composite oxides of Pr-Mn, Pr-Ni, Pr-Co or Mn oxide are used to constitute at least one part or all parts of interface film between a phosphor film and a back electrode film of an AC thin film EL panel; and the panel with such a high contrast as 5:1 even at an illumination of 400 lux has been obtained.

Abstract: A system for resistance welding in which the welding voltage between the electrodes is controlled by changing the pressure applied to the electrodes or the firing phase angle of the welding current in accordance with a reference voltage curve or a reference voltage integration curve. The system comprises a voltage sensor, a reference voltage generator, a differential amplifier, and a pressure control device, or a calculating unit for determining an appropriate firing phase angle of the welding current. The system thus improved can ensure a stable, good welding quality, since the welding voltage is always controlled by a series of optimum welding voltages, during the welding process, in accordance with a reference voltage curve with respect to time, preferably in terms of cycles of the welding current.

Abstract: A method and apparatus for manufacturing an ultrafine particle film which has great practical utility when deposited on an appropriate substrate. The particle film is produced from various ultrafine particles of, for example, metals, oxides, nitrides and carbides, and is produced uniformly, effectively and efficiently with a high degree of reproducibility. According to a first method, an atmosphere at a gas of a reduced pressure is formed in a vessel, and a forced flow of the gas is formed unidirectionally from an evaporation source to the substrate, so that the evaporated matters from the evaporation source are forced to move together with the forced flow of the gas, so that ultrafine particles which are formed through interaction between the evaporated matters and the gas deposited on the substrate thereby forming the ultrafine particle film.

Abstract: A system for resistance welding in which the welding voltage between the electrodes is controlled by changing the pressure applied to the electrodes or the firing phase angle of the welding current in accordance with a reference voltage curve or a reference voltage integration curve. The system comprises a voltage sensor, a reference voltage generator, a differential amplifier, and a pressure control device, or a calculating unit for determining an appropriate firing phase angle of the welding current. The system thus improved can ensure a stable, good welding quality, since the welding voltage is always controlled by a series of optimum welding voltages, during the welding process, in accordance with a reference voltage curve with respect to time, preferably in terms of cycles of the welding current.

Abstract: A gas sensing device comprises a gas sensing element comprising a gas-sensitive resistive film formed of an aggregate of ultrafine particles of a suitable material deposited on the surface of a substrate of an electrical insulator formed with electrodes. In a method of manufacturing such a gas sensing device, a gas-sensitive material is evaporated in a gas atmosphere to provide the gas-sensitive resistive film of ultrafine particles of the material.

Abstract: A gas sensing device comprises a gas sensing element comprising a gas-sensitie resistive film formed of an aggregate of ultrafine particles of a suitable material deposited on the surface of a substrate of an electrical insulator formed with electrodes.