Abstract: A phase-locked loop circuit includes a phase comparator, a filter circuit, a voltage-controlled oscillator, a pull-out state detection circuit, and an FET switch. The phase comparator receives input data and a reference signal and outputs a voltage value representing a phase difference between the input data and the reference signal. The filter circuit generates and outputs a control voltage on the basis of the voltage value representing the phase difference between the input data and the reference signal output from the phase comparator. The voltage-controlled oscillator generates the reference signal on the basis of the control voltage output from the filter circuit and outputs the reference signal to the phase comparator. The pull-out state detection circuit outputs a signal representing a pull-out state when a change amount of the control voltage output from the filter circuit within a predetermined time exceeds a threshold value.

Abstract: A phase locked loop (PLL) circuit used a temperature compensated voltage controlled oscillator (VCO), in which phases and frequencies of the VCO are synchronized with inputted data and the VCO is always controlled to oscillates within a pull in rage of a phase comparator, is provided. The PLL circuit used the temperature compensated VCO provides a temperature/voltage converter used a temperature sensor. By giving an external control voltage to the VCO as an input voltage, the VCO is controlled to oscillate within the pull in range of the phase comparator. With this, a stable PLL operation can be always performed even when an ambient temperature changes.

Abstract: In a feed-forward distortion compensating system, first and second laser diodes are provided on a same semiconductor chip to modulate first and second electric signals in light intensity to produce first and second light signals, respectively. A photoelectric conversion unit converts a part of the first light signal into a third electric signal. A distortion compensating signal generator synthesizes the third electric signal and a fourth electric signal associated with the first electric signal into the second electric signal. The second electric signal is light-intensity-modulated into the second light signal. A light signal synthesizing unit synthesizes the first light signal and the second light signal into a transmission light signal.

Abstract: A clipping distortion controlling circuit for stabilizing an amount of generation of the clipping distortion. A level of the clipping distortion generated by a light-emitting semiconductor laser element is monitored through a light-receiving element and a band-pass filter. A limiter-level of a pre-clipping circuit is changed to be controlled in accordance with the level of the clipping distortion. For this reason, it is capable of coping with the level-fluctuation of the clipping distortion caused by gain-change of an amplifier or by characteristic degradation of the light-emitting element, so that clipping distortion generation has a stabilized characteristic.

Abstract: An analog optical transmission apparatus includes a semiconductor laser module, a bandpass filter, a distortion level detection circuit, a control signal generation circuit, and a distortion erasure circuit. The semiconductor laser module includes a semiconductor laser for converting a multi-carrier analog signal into an optical signal and outputting the optical signal and a light-receiving element for receiving the optical signal from the semiconductor laser and converting the optical signal into an electrical signal. The bandpass filter extracts only a specific distortion component from the electrical signal output from the light-receiving element. The distortion level detection circuit detects a level of the distortion component output from the bandpass filter. The control signal generation circuit generates a control signal corresponding to the distortion component level output from the distortion level detection circuit.

Abstract: In an optical wavelength control apparatus for a laser diode, an optical branching circuit branches a laser beam from the laser diode into first, second, and third branched laser beams. An optical band-pass filter and optical low- and high-pass filters receive the first, second, and third branched laser beams and transmit laser beams having specific optical wavelengths therethrough as transmitted beams. First, second, and third photodiodes convert output beams from these filters into electrical signals and output them as analog voltages. A comparison amplifier compares the analog voltages output from the second and third photodiodes and outputs a comparison result signal. An operational amplifier performs differential amplification of a reference analog voltage from the first photodiode and the output signal from the comparison amplifier, and outputs a control signal. A temperature adjustment element is in tight contact with the laser diode and generates heat, a temperature of which is externally controlled.

Abstract: In the apparatus for driving a laser diode, a light receiving element detects a light output level of the laser diode to produce an electric signal. That is, the light receiving element detects a first electric signal when the laser diode is driven based upon an ON signal, and a second electric signal when the laser diode is driven based upon an OFF signal. A control circuit outputs a control signal in response to the signal. A driving circuit drives the laser diode in response to the control signal such that a difference between the first electric signal and the second electric signal is maintained at a constant value.

Abstract: The present invention relates to a process for producing a W/O/W type multiple emulsion using a polyglycerol polyricinolate (i.e. a polyglycerol ester of a polycondensed fatty acid of caster oil).The use of the polyglycerol polyricinolate is effective in increasing the rate of formation of the W/O/W type multiple emulsion remarkably and giving a W/O/W type multiple emulsion which is stable over a long period of time. The W/O/W type multiple emulsion has also an excellent heat stability and is useful for the production of medicines and cosmetics.

Abstract: The present invention relates to a process for producing a W/O/W type multiple emulsion using a polyglycerol polyricinolate (i.e. a polyglycerol ester of a polycondensed fatty acid of castor oil).The use of the polyglycerol polyricinolate is effective in increasing the rate of formation of the W/O/W type multiple emulsion remarkably and giving a W/O/W type multiple emulsion which is stable over a long period of time. The W/O/W type multiple emulsion has also an excellent heat stability and is useful for the production of medicines and cosmetics.

Abstract: A process is provided for producing a water-oil-water type multiple emulsion comprising:a. adding an emulsifying amount of polyglycerol polyricinoleate to an oil phase;b. forming an oil in water emulsion by adding the product of step a to an aqueous phase;c. inverting the oil in water emulsion of step b into a water in oil emulsion by agitating; andd. forming a water-oil-water emulsion by adding the water in oil emulsion of step c to an outer aqueous phase.The emulsions produced by this process are useful for preparing medicines and cosmetics.

Abstract: The present invention relates to a process for producing a W/O/W type multiple emulsion using a polyglycerol polyricinolate (i.e. a polyglycerol ester of a polycondensed fatty acid of castor oil).The use of the polyglycerol polyricinolate is effective in increasing the rate of formation of the W/O/W type multiple emulsion remarkably and giving a W/O/W type multiple emulsion which is stable over a long period of time. The W/O/W type multiple emulsion has also an excellent heat stability and is useful for the production of medicines and cosmetics.

Abstract: A stable W/O/W type multiple emulsion containing very fine water droplets and suitable for use in the production of foods, cosmetics and medicines is prepared by using a glycerol unsaturated fatty acid ester as an emulsifier for a W/O emulsion.

Abstract: The present invention relates to a process for preparation of dressings comprising W/O/W type multiple emulsions. Dressings comprising a quite stable W/O/W type multiple emulsions can be obtained by using monoerucin, dierucin, or polyglycerol polycondensed ricinoleic acid ester as the emulsifier. A quite fine W/O/W type emulsion can also be obtained, since an O/W emulsion is subjected to a phase inversion to form a W/O emulsion in the first place.

Abstract: The present invention relates to a process for preparation of dressings comprising W/O/W type multiple emulsions. Dressings comprising a quite stable W/O/W type multiple emulsions can be obtained by using monoerucin, dierucin, or polyglycerol polycondensed recinoleic acid ester as the emulsifier.

Abstract: The present invention relates to a process for preparing dressings comprising W/O/W type multiple emulsions. A W/O/W type emulsion can be obtained by phase inversion from W/O type emulsion by adding an aqueous phase to an oil phase containing monoerucin, dierucin, or polyglycerol polycondensed ricinoleic acid ester as the emulsifier under agitating. Also, dressings having an excellent richness can be provided.

Abstract: The present invention relates to a process for the production of a water-in-oil-in-water (W/O/W) type multiple emulsion for foods, which is very fine and exhibits excellent stability. A stable W/O/W type multiple emulsion is obtained by using a polyglycerol polyricinoleate to obtain a fine W/O emulsion in a primary emulsification, and adding a water phase containing an emulsifier to the resulting W/O emulsion and mixing by agitating in a secondary emulsification.

Abstract: In a key telephone system with a plurality of four-wire key telephone sets wherein a two-wire telephone set is connected to a main control device via a pair of speech lines so that intercom speech and office line speech are possible between the two-wire telephone set and other key telephone sets, the improvement wherein said main control device comprises a call signal generating circuit, first transfer switching means for transfer-connecting said speech lines between a pair of office speech lines and a pair of intercom speech lines, second transfer switching means for transfer-connecting said speech lines between said call signal generating circuit and said first transfer switching means, DC loop supervisory means for supervising a DC loop of said speech lines, and a control circuit inputted with an output of said DC loop supervisory means for controlling said first and second transfer switching means in accordance with the states of said office lines.

Abstract: In a signal transmission system of a key telephone system of the type comprising a main device connected to office lines and having an input/output port for transmitting and receiving signals, and a plurality of key telephone sets connected in parallel to the main device through a pair of signal lines for transmitting and receiving various control signals between the main device and the key telephone sets, wherein each of the control signals is constituted by a pulse width modulated time series signal of a predetermined number of bits, respective control signals are inputted and outputted in parallel to and from a bit input/output of the input/output port and wherein transmission and reception of the control signals between the main device and respective key telephone sets are simultaneously performed by parallel input/output operations of the calculating processing unit.

Abstract: A carburetor outer vent control device for use in a fuel system of a motor vehicle of the type including an outer vent provided in a float chamber of the carburetor, a charcoal canister and a fuel vapor line coupling the outer vent with the charcoal canister. The carburetor outer vent control device includes a valve means provided in the fuel vapor line which is only open when an excessive amount of fuel vapor is present in the float chamber and an engine of the motor vehicle is not running.