Abstract: A transmitter using a dual conversion system which effects frequency conversion twice has a local oscillator (113) for generating a first local oscillation signal, a multiplier (118) for multiplying the frequency of the first local oscillation signal to produce a second local oscillation signal, a first mixer (115) for mixing the first local oscillation signal and first IF signal to produce a second IF signal, and a second mixer (120) for mixing the second local oscillation signal and second IF signal to produce a signal to be transmitted. A voltage controlled filter (116) whose center frequency varies with the frequency of the first local oscillation signal is connected to the output of the first mixer (115).

Abstract: An apparatus for controlling a DC motor connected to an intake throttle valve in an internal combustion engine to detect an actual opening degree of the intake throttle valve and to match the actual opening degree with a command opening degree. The apparatus includes a feedback loop for defining a feedback signal indicative of a command to converge the actual opening degree of the control member to the command opening degree by reception of the command opening degree delivered by a command opening degree generating means and the actual opening degree delivered by an actual opening degree detecting means, a combined-signal generating means for combining the feedback signal defined by the feedback loop with the command opening degree delivered by the command opening degree generating means, and a motor driving means for driving the DC motor in response to an output from the combined-signal generating means.

Abstract: A semiconductor light emitting device which allows part of an active layer to generate light by supplying current to the part of the active layer is disclosed. The semiconductor light emitting device includes: a semiconductor substrate having upper and lower surfaces, the upper surface having a stepped portion, the stepped portion dividing the upper surface into at least a first area and a second area; a current confining layer, formed on the upper surface of the substrate, the current confining layer being discontinuous at the stepped portion, the current flowing through an area between the first area and the second area of the substrate; a multilayer structure formed on the current confining layer, the multilayer structure including the active layer; a first electrode which covers only part of an upper surface of the multilayer structure; and a second electrode formed over the lower surface of the substrate.

Abstract: A microwave absorber in a pointed shape, including a phenol resin foam containing a dielectric loss material, is prepared by setting an incombustible sheet container of a same shape in a mold in a pointed shape, pouring the phenol resin to which the dielectric loss material is blended, and foaming and curing. As a result, a semi-incombustible or incombustible microwave absorber of high strength possessing a high microwave absorption capacity in a wideband is obtained.

Abstract: Provided is an improved refrigeration system for pre-cooling natural gas or cooling a mixed refrigerant for natural gas liquefaction in a propane refrigeration process widely used for the liquefaction of natural gas. The system comprises a plurality of plate-fin heat exchangers preferably arranged in a parallel relationship for passing a propane refrigerant as a vertical flow and pre-cooling natural gas or cooling a mixed refrigerant for liquefying natural gas, and a thermo siphon drum for the propane refrigerant consisting of a horizontally disposed, laterally elongated tank. Because the passages of the heat exchanger for the natural gas or the mixed refrigerant extend over their entire length in mutually separate relationship, even when the propane refrigerant, the natural gas or the mixed refrigerant is in both gas and liquid phases, a high efficiency of heat transfer can be attained, and the size of the heat exchanger can be reduced.

Abstract: Provided is a method for liquefying natural gas which can be readily adapted to LNG plants of all sizes without requiring expensive and special heat exchangers. The liquefaction of feed gas of natural gas and recycle natural gas is carried out with a single-component refrigerant or a mixed refrigerant in a high temperature stage, and with a substantially isentropic expansion in a low temperature stage, and a non-liquefied part of the recycle gas after the expansion step is pressurized with a compressor and recycled along with a recycle stream of non-liquefied par of the feed natural gas, the liquefied part by the refrigerant exchanging heat with the non-liquefied part stream produced from the substantially isentropic expansion, in a plate-fin heat exchanger or the like. The compressor is driven by the power obtained by the substantially isentropic expansion.

Abstract: A radio transmitter suitable for a frequency hopping communication system which transmits a phase modulated signal with a minimum of spurious signals and phase noise. A direct digital frequency synthesizer (DDS) generates a frequency hopping signal lying in the VHF band. A first phase locked oscillator reduces the spurious components of the frequency hopping signal to produce a corresponding signal lying in the UHF band. This UHF band signal is used as a reference signal for a second phase locked oscillator which sends the phase modulated signal via a voltage controlled oscillator (VCO) built therein. The second phase locked oscillator includes a modulator for further modulating the phase of the phase modulated signal or a frequency divided version thereof by a modulating signal. The output of the modulator is used as a signal to be compared by a phase comparator or a source of signal to be compared.

Abstract: A method of producing a transparent conductive film provided with supplementary metal lines, comprises the steps of forming a transparent conductive film composed mainly of indium oxide, tin oxide, or antimony oxide on a transparent substrate and forming metal lines through printing on the transparent conductive film by an intaglio or litho offset printing procedure a line pattern of metallorganic ink composed mainly of an organic noble metal containing gold, silver, or platinum and baking it for metallization.

Abstract: A surface electrode on a surface of a LED has a pad, and further, at least first-order branches linearly extending from the pad, second-order branches diverged and linearly extending from the first-order branches, and third-order branches diverged and linearly extending from the second-order branches. The pad out of the surface electrode is not in electrical contact with a underlying semiconductor layer, whereas the surface electrode and the semiconductor layer are in electrical contact with each other at ends of the highest-order branches. Also, the semiconductor layer is provided along a pattern of the surface electrode in a mesa shape. Thus, ineffective light emission underneath the surface electrode is relatively reduced so that external quantum efficiency can be improved, and moreover even shorter-wavelength light can be allowed to go out at high efficiency by omitting a current diffusion layer.

Abstract: A catamaran comprises two single hulls arranged in parallel in the spaced relation to each other, and a deck for connecting the two single hulls, the single hull having a semisubmerged portion and a connecting portion for connecting the semisubmerged portion to the deck, the semisubmerged portion having a maximum width portion where the width of its vertical transverse cross section is largest at a position near the water level, the width of vertical transverse cross section of the semisubmerged portion abruptly decreases upward in the vertical direction from the maximum width portion and gradually decreases downward in the vertical direction from the maximum width portion, the semisubmerged portion having a minimum width portion where the width of vertical transverse cross section becomes smallest after it abruptly decreases upward in the vertical direction, and the width of vertical transverse cross section of the minimum width portion is 60% or less and 30% or more of the width of vertical transverse cross

Abstract: A case body composed of upper and lower halves having a main wall in which there is defined at an intermediate portion thereof a pair of drive shaft insertion holes in right and left portions thereof, and the case body includes two pairs of upper and lower flange members inwardly projected from inner peripheral portions of the drive shaft insertion holes continuous with the main wall. A name plate made of a materials harder than the plastic material of the case body, is attached to an outer surface of the main wall including the right and left drive shaft insertion holes, and the name plate has one or more indexes formed on the outer surface thereof and has a pair of right and left shaft insertion openings defined therein. The positions of the shaft insertion openings correspond to the drive shaft insertion holes defined in the case body.

Abstract: A semiconductor laser device is provided which is constituted by semiconductor materials so as to emit laser light from a cavity end facet, the laser light being excited in a waveguide within an active layer sandwiched between a pair of cladding layers, wherein a window layer made of a semiconductor material having a band gap greater than that of the active layer is formed on the cavity end facet from which the laser light is emitted, so as to have a thickness sufficient to prevent local generation of crystal defects by lattice mismatching between the semiconductor material of the window layer and the semiconductor materials at the cavity end facet. There is also provided a method for producing such a semiconductor laser device with high efficiency.

Abstract: A light wavelength converter which includes a laser beam source for radiating fundamental waves, a first optical waveguide formed on a substrate so as to convert the fundamental waves into harmonics which are radiated through the substrate, a grating coupler provided on the substrate so as to receive the harmonics propagated through the substrate, and a second optical waveguide formed on the substrate, the second optical guide being connected to the grating coupler so as to radiate the harmonics outside.

Abstract: Disclosed is an intaglio printing process which comprises (a) forming an intaglio printing plate having groove patterns, (b) filling said groove patterns with an ink, (c) after drying said ink, forming a curable resin layer on the whole surface of the intaglio printing plate, (d) placing a body to be printed thereon without curing said resin layer, (e) curing the curable resin, and (f) stripping the body from the intaglio printing plate to form the ink patterns corresponding to the groove patterns of the intaglio on the body. There are also disclosed processes for producing a color filter, a black matrix and a circuit board.

Abstract: There is provided a method for the production of a semiconductor laser device which emits laser light from an end facet thereof.

Abstract: Drive wheel slip control system for a vehicle includes means for setting a reference value for slippage of a drive wheel providing an appropriate slip condition, means for reducing the drive wheel torque when the slippage exceeds the reference value, means for detecting the opening degree of an accelerator of a prime mover which drives the drive wheel, and means for correcting the reference value dependent on signals from the detecting means. The vehicle responds to accelerator operation even during control of the drive wheel slip, enabling a sporty travel.

Abstract: A physical quantity control device includes first and second control elements having different sensitivities from one another, the first and second control elements providing outputs to change at least one physical quantity in response to first and second operational quantities individually input to the first and second control elements. First and second computing circuits are provided for computing the first and second operational quantities in response to a deviation between a predetermined target value and the physical quantity, wherein the physical quantity is feedback controlled to converge with the predetermined target value.

Abstract: Disclosed is an optically active compound represented by the formula: ##STR1## wherein R.sub.1 and R.sub.2 are alkyl, alkenyl or alkoxy-alkyl, which may be substituted by halogen, X and U are a direct bond, --O--, --COO-- or --OCO--, Y and Z are a direct bond, --COO--, --OCO--, --CH.sub.2 O-- or --OCH.sub.2 --, A.sub.1 and A.sub.2 are phenylene, cyclohexylene or a phenylene- or cyclohexylene-containing group, p and q are 0 or 1, C* is an asymmetric carbon atom, with the proviso that when Z is a direct bond, q is 0, R.sub.2 is alkyl, Y is a direct bond, --OCO-- or --OCH.sub.2 --. The optically active compound is used as a ferroelectric liquid crystal or an additive to a ferroelectric or non-ferroelectric liquid crystal.

Abstract: A laser beam oscillating apparatus which includes a plurality of semiconductor laser beam oscillators (21, 22, 23) oscillating laser beams of a different wavelength from each other, an optical waveguide (12) formed on a substrate (11) so that the oscillated laser beams propagate therein and are then emitted in the same direction from the output end thereof and an optical coupler (13) to introduce the laser beams into the optical waveguide, thus allowing simultaneous introduction of these semiconductor laser beams of different wavelengths into the optical waveguide and simultaneous output of them in the same direction from the output end thereof.

Abstract: A system for correctively controlling the turning movement of a vehicle, including a device for correcting the turning movement of the vehicle, a sensor for detecting the steering angle of a steering wheel of the vehicle, a steering angle hysteresis storage device for storing the hysteresis of the steering angle, and a reference value arithmetic device for determining a reference value of a physical quantity generated during a turning movement of the vehicle, on the basis of the hysteresis of the steering angle. The system also includes a detector for detecting an actual value of the physical quantity during the turning movement, a calculator for determining a deviation between the reference value and actual value of the physical quantity and a polarity of the deviation, and a control-quantity determining device for determining a control-quantity for the turning movement correcting device on the basis of the deviation obtained in the calculator.