Abstract: A piezoelectric transformer inverter comprises: a piezoelectric transformer for performing voltage conversion of alternating voltage applied between primary electrodes to supply to a load connected to a secondary electrode; a driving-frequency control unit for controlling load current during driving of the load by changing the driving frequency of the piezoelectric transformer; a chopper unit for chopping input voltage applied into the driving-frequency control unit at a frequency of two or more times as high as the driving frequency and for controlling an average input voltage applied into the driving frequency control unit by changing a duty ratio of the chopping operation; and a dimming unit for intermittently stopping the driving frequency control unit by intermittently stopping the operation of the chopper unit at a frequency smaller than the driving frequency of the piezoelectric transformer, wherein even during a period in which the dimming unit is intermittently stopping the chopper unit, signals havi

Abstract: A piezoelectric transformer inverter includes: a piezoelectric transformer, one of whose primary electrodes is grounded, which performs voltage conversion of alternating voltage or direct current voltage applied between the primary electrodes and supplies the converted voltage to a load connected to a secondary electrode; a drive unit for supplying alternating voltage or direct current voltage between the primary electrodes of the piezoelectric transformer; a low-pass type resonance circuit unit inserted between the output of the drive unit and the primary electrodes of the piezoelectric transformer; a duty control unit for controlling ON-Duty of the drive unit so that a value of current flowing into the load coincides with a targeted current value; a phase-difference detection unit for detecting a phase difference between the input voltage and the output voltage of the piezoelectric transformer; and a frequency control unit for controlling a driving frequency of the drive unit.

Abstract: A piezoelectric transformer inverter includes an inverter unit and a step-down chopper unit. The inverter unit includes a ceramic piezoelectric transformer whose secondary terminal is to be connected to a fluorescent tube, a drive unit which is connected to a primary terminal of the ceramic piezoelectric transformer, and an inverter control circuit for controlling luminance of the fluorescent tube to a desired value. The step-down chopper unit includes a switching device which is disposed on the side where the voltage of the inverter unit is input, a free wheeling device connected between the switching device and a reference potential, and a PWM feedback control circuit for providing a feedback control to maintain an average voltage of the rectangular-wave voltage of the switching device constant.

Abstract: Since a backlighting apparatus 1 for liquid crystal display is constituted such that a light guiding plate 2 and a frame 3 are molded together as a single unit provided with a deformation relaxation design, an attaching unit and parts, such as attaching feet and screws, for attaching the light guiding plate 2 to the frame 3 are not required, thereby making it possible to reduce the thickness and size of the backlighting apparatus 1 for liquid crystal display which has been restricted by the sizes of these parts.

Abstract: The present invention provides an aromatic polyamide bristle exhibiting excellent chemical resistance to acid, alkali, etc., and good mechanical properties such as rigidity, strength and modulus and heat-resistance, suitable for industrial applications such as tension member, fishing line and catheter, having a single fiber fineness of 10 to 200 denier, a flatness of 3 or below and mechanical properties characterized by a tensile strength of 15 g/de or above, an elongation at break of 4.0% or below and an initial modulus of 500 g/de or above and formed from an optically isotropic solution.

Abstract: A boosting drive circuit includes first and second series combinations of a coil and a transistor. The two series combination of a coil and a transistor are connected in parallel. The middle points between the coils and the transistors are connected to respective primary electrodes of a piezoelectric transformer. The transistors are alternately operated with a two-phase drive circuit. Thus, a boosting drive circuit providing for the class "semi-E" operation is formed. A driving voltage control circuit controls an average voltage applied to the input terminal of the boosting drive circuit to ensure that current on the secondary electrode side of the piezoelectric transformer is controlled at a predetermined value is provided between the input power supply and the boosting drive circuit.

Abstract: An electron-emitting device having a electron-emitting portion between electrodes on a substrate comprises a region A and a region B, the region A being electrically connected through the region B to at least one of the electrodes, electric conductivity .sigma..sub.1 of the material mainly constituting the region A and electric conductivity of the material .sigma..sub.2 mainly constituting the region B being in the relation of .sigma..sub.1 >.sigma..sub.2, and the region A being the electron-emitting portion. An electron beam-generating apparatus and image-forming apparatus comprise the electron-emitting device and a modulation means for modulating the electron beams emitted from the electron-emitting elements in accordance with information signals.

Abstract: An electron-emitting device comprising a pair of device electrodes and an electroconductive film including an electron-emitting region is manufactured by a method comprising a process of forming an electroconductive film including steps of forming a pattern on a thin film containing a metal element on the basis of a difference of chemical state, and removing part of the thin film on the basis of the difference of chemical state.

Abstract: An electron-emitting device having an electron-emitting portion between electrodes on a substrate comprises a region A and a region B, the region A being electrically connected through the region B to at least one of the electrodes, electric conductivity .sigma..sub.1 of the material mainly constituting the region A and electric conductivity of the material .sigma..sub.2 mainly constituting the region B being in the relation of .sigma..sub.1 >.sigma..sub.2, and the region A being the electron-emitting portion. An electron beam-generating apparatus and image-forming apparatus comprise the electron-emitting device and a modulation means for modulating the electron beams emitted from the electron-emitting elements in accordance with information signals.

Abstract: An aromatic polyamide resin composition useful for producing compression-molded resin articles having an excellent impact strength, comprising 3 to 40% by weight of PEEK resin fibers, the balance consisting of an aromatic polyamide resin particles, and optionally, 10% by weight or less of PTFE resin particles, which effectively enhance the abrasion resistance of the compression-molded resin article.

Abstract: An aromatic polyamide resin composition useful for producing compression-molded resin articles having an excellent impact strength, comprising 3 to 40% by weight of PEEK resin fibers, the balance consisting of an aromatic polyamide resin particles, and optionally, 10% by weight or less of PTFE resin particles, which effectively enhance the abrasion resistance of the compression-molded resin article.

Abstract: A vitreous film containing, e.g., 30-90 wt. % of Sn, 1-20 wt. % of P, 0.1-20 wt. % of Pb, 2-30 wt. % of 0 and 5-35 wt. % of F is formed by vapor deposition on a substrate such as glass, metal, plastic or ceramic. A light-absorbing substance can be incorporated in the vitreous film to provide a recording layer for a heat-mode optical recording medium capable of causing decoloration or formation of pits on irradiation with a laser beam.

Abstract: A new type of aromatic polyamide powder including a large number of fine coalescible particles which have an average size of from 0.1 to 10 .mu.m, which include at least one aromatic amide polymer including 40 to 100 molar % of recurring m-phenylene isophthalamide units and 0 to 60 molar % of at least one other type of additional recurring aromatic amide units, for example, m-phenylene terephthalamide units, and which coalesce with each other to form porous agglomerates having an average size of from 10 to 400 .mu.m and a surface area of from 1 to 20 m.sup.2 /g, and can be compression molded, optionally in mixture with a reinforcing additive, for example, aromatic polyamide fibers having a length of 3 mm or less, at a temperature of 200.degree. to 400.degree. C. under a pressure of 300 to 1000 kg/cm.sup.2 for 20 minutes to 5 hours, to produce shaped articles having excellent mechanical properties and appearance.

Abstract: A new type of aromatic polyamide powder including a large number of fine coalescible paticles which have an average size of from 0.1 to 10 .mu.m, which include at least one aromatic amide polymer including 40 to 100 molar % of recurring m-phenylene isophthalamide units and 0 to 60 molar % of at least one other type of additional recurring aromatic amide units, for example, m-phenylene terephthalamide units, and which coalesce with each other to form porous agglomeraters having an average size of from 10 to 400 .mu.m and a surface area of from 1 to 20 m.sup.2 /g, and can be compression molded, optionally in mixture with a reinforcing additive, for example, aromatic polyamide fibers having a length of 3 mm or less, at a temperature of 200.degree. to 400.degree. C. under a pressure of 300 to 1000 kg/cm.sup.2 for 20 minutes to 5 hours, to produce shaped articles having excellent mechanical properties and appearance.

Abstract: An optical device comprises an optical waveguide constituted of as a basic unit a core layer of a material having a relatively high refractive index and a clad layer of a material having a relatively low refractive index and covering said core layer, and heating means for heating said core layer to change the refractive index thereof, characterized in that when said core layer is constituted of a liquid, said core layer is heated by said heating means to a temperature such that said core layer does not boil.

Abstract: An optical device comprises an optical waveguide having, as a basic unit, a core layer of a liquid having a relatively high refractive index and a clad layer having a relatively low refractive index and covering said core layer, and a heat-generating means for heating a part of said core layer to form a vapor bubble in said liquid of said core layer.

Abstract: An anisotropic aromatic polyamide dope comprising more than 10% by weight of an aromatic polyamide and a solvent for the polyamide, said polyamide consisting essentially of, at least 5 mole% but less than 35 moles%, based on its entire units, of an only partially p-oriented structural unit expressed by the following formula ##STR1## wherein Ar.sup.1 is a divalent aromatic ring whose chain-extending bonds are coaxial or parallel, X is a member selected from the group consisting of O, S and NH, and the NH group bonded to the benzene ring of the above benzoxazole, benzothiazole or benzimidazole ring is meta or para to the carbon atom of said benzene ring.

Abstract: A process for preparing aromatic polyamides which comprising contacting (I) a solution or dispersion consisting of a solution or dispersion in a polar, non-basic and inert organic liquid medium of at least one starting material selected from the group consisting ofI. an aromatic aminocarboxylic acid halide hydrohalogenide,Ii. a mixture of an aromatic dicarboxylic acid halide and an aromatic diamine dihydrohalogenide, andIii. a low molecular weight aromatic polyamide having an inherent viscosity of no greater than 0.2 as measured on a solution of 0.5 gram of the polyamide in 100 ml of concentrated sulfuric acid at 30.degree.C., with(II) an aqueous slurry consisting of a dispersion in water of a sodium carbonate hydrate.