Abstract: A band-stop filter for VHF-UHF band comprises at least three series resonance circuits and at least two transmission lines each connected between the series resonance circuits. One of the transmission lines, which is connected to the input terminal of the band-stop filter, has an electrical length which is shorter or longer than the quarter wavelength of the center frequency of the stop band by more than 20 but less than 50 percent. When a band-stop filter comprises four transmission lines, one of the transmission lines, which is connected to the output terminal of the band-stop filter, has the same length as the transmission line connected to the input terminal. With this arrangement, the band-stop filter exhibits a sharp attenuation characteristic in a frequency range below or above the center frequency.

Abstract: A plurality of magnetic field sensors are mounted adjacent the periphery of an induction heating coil of flat, spiral configuration which is energized by ultrasonic frequency energy to generate a time-varying magnetic field. The magnetic field sensors are connected in a ciruit to produce an output signal when a magnetic utensil load is placed asymmetrically with respect to the center of the induction heating coil. In response to sensor output exceeding a predetermined value a warning indication is provided. The ultrasonic energy level is reduced in response to the warning indication to minimize radio interference which would otherwise occur due to leakage magnetic flux.

Abstract: An ultrasonic transducer array for arc scan imaging systems comprises a plurality of elongated piezoelectric transducers arranged successively to define a convexed energy radiating surface. A plano-concave acoustic diverging lens is attached to the convexed surface to diverge the acoustic energy transmitted from the transducers in an increased steering angle. The transducers are assembled on an impedance matching layer which defines the convexed radiating surface. The acoustic impedance of the diverging lens is substantially equal to the acoustic impedance of the human body, while the acoustic impedance of the impedance matching layer is greater than that of the human body.

Abstract: This invention discloses an engine rotation sensor which can generate angle- and timing-pulses from one sensor. The ratio of the intervals between these pulses generated by the rotation sensor is determined. The crank angle pulses and the timing pulses are discriminated depending on whether this ratio is less than or equal to a predetermined value, or not. The injection of fuel of each injector is controlled by a pulse which is discriminated as a timing pulse.

Abstract: A coating composition for solar selective absorption comprising, in solvent, particles of an inorganic black pigment dispersed in a dissolved binder of a thermosetting acrylic resin and particles of a low molecular weight fluorocarbon resin contained in an amount of 5-15 parts by weight per 100 parts by weight of the acrylic resin. The inorganic black particles have a size of 0.01-0.5 microns and are contained in an amount of 45-65 parts by weight per 100 parts by weight of the acrylic resin. An article having a metal substrate and a paint film formed thereon from the composition in a dry thickness of 1.5 microns or more is also described.

Abstract: A functional electric device is described, which device comprises a functional material layer, and a pair of electrodes separated from each other and electrically contacting with the functional material layer. At least one of the pair of electrodes is made of copper or an alloy of copper and a copper inactivating agent is present between the functional material layer and the at least one of the paired electrodes. The functional electric device includes heat-sensitive, fusing and photovoltaic elements.

Abstract: An ink jet recording sheet comprising a paper support applied on at least one surface thereof or internally with a composition which comprises an aqueous dispersion of polyvinylpyrrolidone, vinylpyrrolidone-vinyl acetate copolymer or a mixture thereof serving as a binder or sizing agent and a white filler. The white filler is contained in a weight ratio, to the binder, of 10:1 to 0.2:1 when the composition is applied on the surface of the paper support. When the composition is internally incorporated in the recording sheet, it comprises 10 to 60 parts by weight of the filler and 2 to 20 parts by weight of the binder per 100 parts by weight of pulp.

Abstract: A portable video tape recorder for broadcasting applications comprises a pair of video heads mounted diametrically opposite to each other on the circumference of a rotary cylinder. High and low frequency carriers are modulated by frequency modulators with I and Q signals, respectively, and frequency division multiplexed for application to the video heads. The frequency values of the carriers are selected so that third-order distortion noise caused by the hysteresis characteristics of the video heads and the magnetic tape may fall within a frequency range differing from the frequencies of the modulated carriers by an amount greater than the bandwidth of the I and Q signals which are demodulated by frequency demodulators to prevent the occurrence of beat interference in the frequency band of the reproduced video signal.

Abstract: Ultrasonic echo signals are successively sampled and converted to digital echo data which are written into a first digital memory column by column and then read out row by row into a first buffer memory. The digital echo data which are derived in response to beams successively transmitted in a predetermined direction are written into columns of a second digital memory and read out of the memory in rows into a second buffer memory. The data stored in the first and second buffer memories are read out for digital-to-analog conversion and selectively applied within a television "frame" interval to control electron beam intensity of a single cathode ray tube so as to present tomographic and cardiographic images in different display areas of the tube.

Abstract: In a bandpass filter having five or more resonator stages, a sub transmission line is coupled to the main transmission line at the first and fourth resonators. The first to fourth resonators provide peak attenuation points at both sides of the center frequency in the attenuation curve, while the remaining resonators following the fourth resonator further sharpen the attenuation characteristics of the bandpass filter. The main and sub transmission lines may be formed by striplines on a printed circuit board, while the sub transmission line can be capacity coupled to the main transmission line. Coupling capacitances are freely set by setting the length of each gap between adjacent striplines to a desired value. Thus, the peak attenuation points can be accurately controlled to provide a bandpass filter having superior characteristics.

Abstract: In a nonimpact printer a device is provided for feeding a constant pressure fluid to a nonimpact printing head reciprocally movable to scan across a recording sheet. The feeding device is formed with a pair of identical first and second chambers connected respectively to first and second sections of a conduit through which the fluid is supplied from a source to the device. Fluid communication is established between the first and second chambers by a connecting channel which is smaller in cross section than the cross section of the first and second chambers and is connected to the printing head through a narrow passageway.

Abstract: This invention relates to a steam generator for evaporating from a vaporizing portion (17) thereof a liquid (12) sucked up by means of a liquid sucking-up member (10) to provide a steam generator which is capable of vaporizing a liquid efficiently in a short time by application of heat from a heating unit (13) and air fed from a fan (15).

Abstract: A screw tightening apparatus comprises a motor-driven screwdriver bit supported on a base for tightening a screw with a torque which is detected as a reactive force acting on the base by a torque detector. An output signal from the torque detector is amplified and delivered to a comparator in which the signal is compared with a signal from a torque setting device which is indicative of a desired torque with which the screw is to be tightened. When the signals agree with each other in the comparator, the latter produces an output signal which is supplied to a switch which in turnde-energizes an electric or pneumatic motor of the screw tightening apparatus. An adjustable time-delay circuit is connected between the comparator and the switch to delay the signal from the comparator for a period of time which may be varied dependent on the material into which the screw is to be driven and the pitch and material of the screw in use.

Abstract: A wideband tuner for television signals in the VHF, CATV and UHF bands comprises a VHF tuning section coupled to a VHF receiving terminal, a CATV tuning section coupled to a CATV receiving terminal and a UHF tuning section. A switch selectively couples the UHF section to the output of the CATV tuning section or signals from a UHF receiving terminal. Each of the CATV and UHF tuning sections includes a differential mode modulator. In the CATV reception mode, the modulator of the CATV section converts the received CATV signal on an upper-side band differential mode to a UHF frequency, while the modulator of the UHF section converts the UHF frequency CATV signal to the standard intermediate frequency in a lower-side band differential mode. In the UHF reception mode, the UHF section modulator converts the UHF signal in an upper-side band differential mode to the standard intermediate frequency, while the CATV section is disabled.

Abstract: In a gas laser in which a mixture of gases is excited under the influence of an electric field, a first constituent gas of the mixture is introduced into a laser tube to allow a discharge to occur in the introduced gas at predetermined partial pressure. A second constituent gas of the mixture is then introduced into the laser tube until the combined gases reach the normally operating pressure of the mixture to allow a discharge to occur in the later introduced gas.

Abstract: Disclosed is an electrochemical double-layer capacitor which comprises a capacitor element having a pair of polarization electrodes and a spacer interposed between the electrodes and impregnated with an electrolyte solution, and a film enclosure made of two film sheets which have been thermally bonded by heat sealing along their entire periphery. The film sheets are bonded directly or through a heat-fusible resin plate having an opening in which the capacitor element is received. When using the heat-fusible resin plate, the film sheet is made electrically conductive for allowing easy connection to electric appliances or allowing easy connection of a plurality of capacitor elements in series.

Abstract: An electroluminescent semiconductor device comprising bodies of conductive and resistive crystalline gallium nitride (GaN) which are successively epitaxially deposited on a surface of a heat-treated sapphire substrate, and a body of insulative crystalline gallium nitride epitaxially deposited on the resistive body.

Abstract: An ink jet printing head comprises laminar airflow chamber having a front channel through which a combined stream of air and ink droplets is discharged toward a writing surface, and a rear channel axially aligned with the front channel connected to a source of liquid. The chamber is further provided with an air intake connected to a pressurized air supply source for directing an airstream to a point between the front and rear channels so that the airstream makes a sharp turn at the entry into the front channel with the result that a sharp pressure gradient is produced in the liquid discharge path. An electrode is provided for establishing a field between the front channel and the liquid's meniscus at the exit end of the rear channel to cause the latter to extend toward the front channel by combined effects of the potential and pressure gradients and to be torn apart into a droplet which is carried by the airstream discharged through the front channel.

Abstract: An ink jet printing head comprising a nozzle plate having a plurality of nozzles successively arranged in a row. An airflow chamber is in communication with the nozzles for discharging air and ink therethrough to a writing surface and connected to a source of pressurized air for causing an airstream to make sharp turns at the entry into the nozzles creating a plurality of sharp pressure gradients. A liquid chamber is located behind the airflow chamber and connected to a source of ink. A meniscus forming member is located between the air and liquid chambers for causing the ink to form at least one meniscus by surface tension over an area extending parallel with the row of nozzles. Under the influence of the pressure gradients the meniscus of the ink is contoured into a plurality of surfaces convexed toward the nozzles.

Abstract: A conductive pyrolytic product obtained by thermally treating spefici types of heat-resistant polymers including polyamide-imide, an aromatic polymer having a heterocyclic ring of a specific type and an aromatic polyamide under certain temperature and atmospheric conditions. A conductive composition using the pyrolytic product in the form of a powder is also disclosed.