Meiji Milk Products Company, Limited

Nec Corporation

Toshiro Yoshida

Takeshi Takahashi

Yasuyuki Takahashi

Shigeru Tamai

Shigeru Aizawa

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.

PLL circuit used temperature compensated VCO

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.

Feed-forward type distortion compensating system with less distortion quantity

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.

Clipping distortion controlling circuits

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. The distortion erasure circuit generates a distortion signal having the same level and phase as those of a distortion from the semiconductor laser on the basis of the control signal from the control signal generation circuit and cancels the distortion from the semiconductor laser using the generated distortion signal.

Analog optical transmission apparatus

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. A temperature adjustment circuit controls the temperature of heat from the temperature adjustment element on the basis of the control signal.

Laser diode optical wavelength control apparatus

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.

Method and apparatus for driving laser diode in which deterioration of

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.

Process for producing W/O/W type multiple emulsion for medicines

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.

Process for producing a W/O/W type multiple emulsion for medicines,

A process is provided for producing a water-oil-water type multiple emulsion comprising:

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.

Process for producing W/O/W type multiple emusion

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.

Process for preparation of dressings comprising W/O/W type multiple

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.

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.

Process for preparing dressings comprising W/O/W type multiple emulsions

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.

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Tokyo, Japan

Toshiro Yoshida