Abstract: The present invention relates to a technology of a crosspoint switch circuit applied to a cross-connect apparatus, an ADM or the like employed in an optical network.

Abstract: The present invention relates to a technology of a crosspoint switch circuit applied to a cross-connect apparatus, an ADM or the like employed in an optical network.

Abstract: According to a PLL circuit of the present invention, an output of a phase comparator is adjusted according to a space-to-mark transition-probability of an input signal so that an output of a voltage controlled oscillator has a predetermined frequency and phase. Therefore, even when a phase of a timing clock is set other than at 0, an output of the PLL circuit can be kept at the set phase, irrespective of the space-to-mark transition-probability. By using the PLL circuit as such in an optical communication apparatus and an optical communication system, a discrimination point can be kept almost fixed, and therefore, it is possible to lower an error rate.

Abstract: An optical modulator having a voltage-optical output characteristic in which optical output varies periodically with respect to a voltage value of an electrical drive signal is driven by a modulator driving voltage signal, which has an amplitude of 2·V&pgr; between two light-emission culminations or two light extinction culminations of the voltage-optical output characteristic. A low-frequency superimposing unit superimposes a prescribed low-frequency signal on the modulator driving voltage signal, and an operating-point controller controls the operating point of the optical modulator by detecting operating-point drift of the optical modulator based upon the low-frequency signal component contained in an optical signal output from the optical modulator and controlling the bias voltage of the optical modulator in dependence upon the drift of the operating point of the optical modulator.

Abstract: A recirculation exhaust gas extracted from the exhaust passage of an internal combustion engine and flowing through a recirculation passage. A recirculation control valve (6) controls the flow of the recirculation exhaust gas in the recirculation passage. A recirculation pipe (7) forming the recirculation passage has a hot or contact section (7c, 7e) extending near and along an exhaust manifold (1). The recirculation pipe (7) and the exhaust manifold (1) are covered with a heat-insulation cover (10). The drop of the temperature of the recirculation exhaust gas flowing through the recirculation passage is suppressed and the deposition of deposits including carbon in the recirculation control valve (6) is suppressed.

Abstract: An optical modulator having a voltage—optical output characteristic in which optical output varies periodically with respect to a voltage value of an electrical drive signal is driven by a modulator driving voltage signal, which has an amplitude of 2·V&pgr; between two light-emission culminations or two light extinction culminations of the voltage—optical output characteristic. A low-frequency superimposing unit superimposes a prescribed low-frequency signal on the modulator driving voltage signal, and an operating-point controller controls the operating point of the optical modulator by detecting operating-point drift of the optical modulator based upon the low-frequency signal component contained in an optical signal output from the optical modulator and controlling the bias voltage of the optical modulator in dependence upon the drift of the operating point of the optical modulator.

Abstract: An exhaust gas purification system of an internal combustion engine having a bypass exhaust gas passage, openable through a switch-over valve, branched from an exhaust pipe at a location downstream of a catalytic converter and again merged into the exhaust pipe at a downstream point, an adsorbent installed in the bypass exhaust gas passage which adsorbs unburned component of the exhaust gas, and an EGR pipe which recirculates the exhaust gas including the unburned components at a location upstream of the catalytic converter, wherein the EGR pipe is made of metal such as stainless steel and is connected to the bypass exhaust gas passage such that the recirculation pipe is brought into thermal contact with the exhaust pipe, thereby enabling to effectively prevent blocking or corrosion of the EGR pipe or switch-over valve from occurring. The inner wall of the recirculation pipe is formed with liquid repellent and oil repellent film so as to overcome moisture-related problems more effectively.

Abstract: An optical modulator having a voltage—optical output characteristic in which optical output varies periodically with respect to a voltage value of an electrical drive signal is driven by a modulator driving voltage signal, which has an amplitude of 2·V&pgr; between two light-emission culminations or two light extinction culminations of the voltage—optical output characteristic. A low-frequency superimposing unit superimposes a prescribed low-frequency signal on the modulator driving voltage signal, and an operating-point controller controls the operating point of the optical modulator by detecting operating-point drift of the optical modulator based upon the low-frequency signal component contained in an optical signal output from the optical modulator and controlling the bias voltage of the optical modulator in dependence upon the drift of the operating point of the optical modulator.

Abstract: Disclosed are a phase detector for detecting the phase difference between a data signal and a clock signal, and a timing extracting circuit for controlling the phase of the clock signal so that the phase relationship between the clock signal and the data signal is optimal by using the phase detector. The phase detector includes an edge detector for generating an edge signal at the rising edge and the falling edge of the data signal, and a D flip flop (D-FF) for storing and outputting the logical value of the clock signal at the time of generation of the edge signal, and holding the logical value until the generation of the next edge signal, thereby outputting a signal corresponding to the phase difference between the data signal and the clock signal. A clock generator in the timing extracting circuit having a PLL structure controls the phase of the clock signal so that the difference becomes optimal.

Abstract: The present invention relates to a filter circuit which is suitable for use in an integrated circuit formed of transistors or field effect transistors, and controls the frequency band of the amplifying circuit used for the signal receiver, for example, within an optical communications system. The filter circuit includes a first transistor (T1) having a base or gate grounded with high-frequency component via a first resistor (R1); and a second resistor (R2) and a capacitor (C1) each having one end connected to the emitter or source of the first transistor (T1) and the other terminal grounded with high-frequency component. The filter circuit acts as a circuit in which the first transistor (T1) inputs the current (Iin) at a juncture at which the second resistor (R2) and the capacitor (C1) are connected therewith and outputs its collector or drain current (Iout).

Abstract: The invention provides a pneumatic tire in which each sidewall covering and protecting the side face of the carcass has a double-layer structure consisting of an inner layer adjacent to the carcass and an outer layer disposed outwardly on the inner layer and which is characterized in that the rubber component of the rubber composition constituting the inner layer consists essentially of 10 to 30% by weight of at least one rubber having a low degree of unsaturation selected from the group consisting of halogenated butyl rubber and ethylene-propylene-diene rubber and 90 to 70% by weight of at least one rubber having a high degree of unsaturation selected from the group consisting of natural rubber, isoprene rubber, butadiene rubber and styrene-butadiene rubber and that the rubber component of the rubber composition constituting the outer layer consists essentially of 30 to 60% by weight of at least one rubber having a low degree of unsaturation selected from the corresponding group defined above and 70 to 40% b

Abstract: A processing device for processing sheet-like media via immersion in a special fluid, for example, for renewing a copy sheet by removing printed material such as toner therefrom. The processing device has a tank accommodating a fluid therein; a sheet feeding device for feeding a sheet into the fluid in the tank, a sheet accommodating device for accommodating a sheet, a sensing device for outputting a signal responsive to a state of the sheet in the sheet accommodating device, and a changing device for changing a relative position between the tank and the sheet accommodating device, the relative position including a retracted position where the sheet accommodating device is positioned outside the tank and an operating position where the sheet accommodating device is positioned within the fluid in the tank, the changing device changing the relative position in response to the signal outputted by the sensing device.

Abstract: A high speed electronic circuit has a cascode circuit configuration and is provided with a bias current source (CS.sub.0) between an emitter and a base of a load transistor (Q) in the cascode circuit configuration for compensating a base-emitter voltage (V.sub.BE) of the transistor to eliminate an adverse effect of charging and discharging at a stray capacitor (C) which can be connected between the base and the emitter of the transistor. The high speed electronic circuit can be applied to an; circuit, a level shift circuit, a level shift discrimination circuit, a signal distribution circuit, a signal synthesization circuit and a frequency band control circuit.

Abstract: A filter circuit and a filter integrated circuit capable of being used in a high frequency band includes a first resistor R.sub.1 connected between an input signal source and an emitter of a common-base transistor TR.sub.1, a first capacitor C.sub.1 connected between said input signal source and a reference voltage point, a second capacitor C.sub.2 connected between said input signal source and a collector of the common-base transistor TR.sub.1, and a second resistor R.sub.2 connected between the collector of the common-base transistor and the reference voltage point. Thus, a low-pass filter which operates in a high frequency band and suppresses the influence of characteristic parameters over the filter characteristic can be constructed.

Abstract: A filter circuit and a filter integrated circuit capable of being used in a high frequency band comprises a first resistor R.sub.1 connected between an input signal source and an emitter of a common-base transistor TR.sub.1, a first capacitor C.sub.1 connected between said input signal source and a reference voltage point, a second capacitor C.sub.2 connected between said input signal source and a collector of the common-base transistor TR.sub.1, and a second resistor R.sub.2 connected between the collector of the common-base transistor and the reference voltage point. Thus, a low-pass filter which operates in a high frequency band and suppresses the influence of characteristic parameters over the filter characteristic can be constructed.

Abstract: An electronic circuit package which includes first and second conductive metal members and a circuit board held between the first and second metal members and having a cutout in which an electronic circuit part is accommodated and a process of producing such electronic circuit package are disclosed. With the electronic circuit package, deterioration of a high speed characteristic of an electronic circuit part accommodated in the package is minimized, and accordingly, when the electronic circuit package is applied to an IC for very high speed optical communications for use with an optical repeater or the like, a very high speed system can be realized. By assembling the components in accordance with a predetermined order, facility in process of production and improvement in reliability of products are attained.

Abstract: An electronic circuit package which includes first and second conductive metal members and a circuit board held between the first and second metal members and having a cutout in which an electronic circuit part is accommodated and a process of producing such electronic circuit package are disclosed. With the electronic circuit package, deterioration of a high speed characteristic of an electronic circuit part accommodated in the package is minimized, and accordingly, when the electronic circuit package is applied to an IC for very high speed optical communications for use with an optical repeater or the like, a very high speed system can be realized. By assembling the components in accordance with a predetermined order, facility in process of production and improvement in reliability of products are attained.

Abstract: Disclosed is an equalizing and amplifying circuit in an optical signal receiving apparatus comprising a preamplifier circuit having an input terminal connected to the output of a light receiving element. The preamplifier circuit amplifies the electrical signal from the light receiving element and outputs an amplified signal. An automatic gain control circuit is connected to the output of the preamplifier circuit. The preamplifier circuit comprises a transistor having a common-base, a current source connected to the emitter of the transistor for supplying a bias current to the transistor, and a load resistor connected to the collector of the transistor. The emitter of the transistor is connected to the input terminal, and the collector of the transistor is connected to the output terminal. A negative influence caused by mounting the circuit on a package is avoided and the circuit operates stably in a high frequency range.

Abstract: A data delay circuit includes a first transistor, and a second transistor having a base, an emitter and a collector. Input data is applied to the bases of the first and second transistors. A constant-current source is coupled between the emitters of the first and second transistors and a negative power source. A capacitor is connected between the collector of the first transistor and the collector of the second transistor. The data delay circuit further includes a third transistor and a fourth transistor. The emitters of the third and fourth transistors are connected to the collectors of the first and second transistors, respectively. The bases of the third and fourth transistors are provided with control data having a polarity opposite to that of the input data and having an adjusted amplitude level corresponding to a desired delay time to be given the input data. First and second load resistors are respectively coupled to the collectors of the third and fourth transistors through a positive power source.