Nec Corporation

Gc Corporation

Nobutaka Watanabe

Hiroshi Kamohara

Masayuki Yamaguchi

Takefumi Oguma

Shunichi Futami

Tadayuki Iwano

Masao Abiru

Makiko Takeo

Yuichi Odagiri

Tsukasa Takehana

A stirring mixer for a dental impression material to decrease bubbles to be generated in a mixed dental impression material and the material to be left in a tubular main body, the mixer has a tubular main body wherein a discharging portion is provided following the mixing portion via a throttling portion from an injecting portion to which two pastes are injected, and a stirring rod with protruding stirring blades is rotated by a motor, leading ends of 1blades are positioned in a largest diameter portion of the throttling portion, leading ends of 2, 3and 4blades are positioned in an inner diameter portion of the mixing portion, 1blade in a rotational direction and interval between 3and 4blades is wider than that between the other adjacent blades, and opposing faces of 3and 4blade to each other bulge towards the other blades.

Stirring mixer for dental impression material

A heating element device has a laminate of a plurality of heating element plates, each of the heating element plates having an insulator and a resistor, which is capable of generating heat upon the supply of electric power, provided on the insulator. The plurality of heating element plates are each independently controllable with respect to energization. The heating element device also has a temperature detection plate having an insulator and a resistor, capable of undergoing a change in resistance value upon a change in temperature, provided on the insulator.

Heating element device, heating element mounted structure, temperature control circuit, temperature control apparatus, and module

To provide a dental alginate impression material composition without the defects of the conventional alginate impression material compositions using a pH indicator, that the confirmation of the completion of the gelation is inaccurate and difficult, and that they are poor in the affinity with water to be used during the mixing, the dental alginate impression material composition containing an alginate, a gelling reaction material, a gelling adjustment material, and a filler as major components further contains 0.001 to 0.1% by weight of one or more pH indicators selected from Cresol Red, &agr;-naphtholphthalein, Tropaeolin OOO, Thymol Blue, and phenolphthalein; 0.1 to 10% by weight of a water-soluble polyether that is a liquid at 25 &deg; C.; and 0.001 to 5% by weight of an inorganic pigment and/or an organic pigment having a color distinctly different from a color tone caused by color formation of the pH indicator during the gelation upon mixing with water.

Dental alginate impression material composition

The dental alginate impression material comprising a main paste containing an alginate, water and a filler as major components and a setting paste containing calcium sulfate and a liquid component as major components, the both pastes being to be mixed and set, wherein the main paste further contains 0.01 to 15% by weight of one or two or more polysaccharides selected from the group consisting of carrageenan, pullulane, curdlan, xanthane gum, gellan gum, pectin, konjak glucomannan, xyloglucan, guar gum, gum arabic, and locust bean gum, and the setting paste further contains 0.5 to 50% by weight of polybutene, is provided to thereby make the composition superior in preservability, and free from change of viscosity of the main paste with time, from liquid separation and deterioration of the setting paste, and from a delay in setting time due to the preservation.

Two-paste dental alginate impression material

An optical surge suppressing apparatus includes an output light level compensating circuit, an optical surge compressing circuit, and an optical amplifier. The output light level compensating circuit compensates for a level drop generated in input signal light. The optical surge compressing circuit suppresses an optical surge generated in the input signal light. The optical amplifier outputs the input signal light in which the level drop is compensated for by the output light level compensating circuit and the optical surge is suppressed by the optical surge compressing circuit.

Optical surge suppressing apparatus

A root canal filling material is disclosed, including (A) from 1 to 50% by weight of guttapercha and/or trans-polyisoprene, (B) from 0.1 to 10%, by weight of polybutene having a number average molecular weight of from 600 to 4,000, (C) from 0.1 to 10% by weight of ester gum, (D) from 0.1 to 20%, by weight of paraffin wax, and (E) from 10 to 95% by weight of one or two or more inorganic fillers selected from zinc oxide, barium sulfate and calcium hydroxide. The root canal filling material of the invention has high adhesion to root canal walls and a sufficient working time and can be used in a method of filling a root canal upon heat softening during the root canal treatment.

Root canal filling material

It is the object of the invention to provide an optical signal receiving apparatus, which is used in a narrow band WDM optical transmission system, and never misguidedly receives an adjacent optical signal, when an optical signal to be received is down. An optical signal to be received is extracted from plural WDM optical signals by an optical BPF, a central wavelength of which coincides with the wavelength of the optical signal to be received, and converted into an electrical signal by the O/E converter. A tone-signal extracting circuit extracts the frequency component of the tone-signal, which is superposed on the optical signal with the wavelength equal to the central wavelength of the optical BPF. If the extracted signal level of the tone signal is lower than that of a predetermined standard voltage, a comparator supplies a reset signal to an electrical signal decision circuit. If the optical signal with a desired wavelength is down, the output level of a tone-signal extracting circuit becomes low, and the electrical signal decision circuit is reset. Then, even if the clock signal of the adjacent optical signal is extracted, the adjacent optical signals is not misguidedly discriminated and regenerated by the electrical signal decision circuit.

Optical receiving apparatus

A modulating circuit for a semiconductor optical modulator is composed of a driver 3 DC-coupled to an optical modulator 2, a load resistor 4 connected in parallel to the modulator 2, and a constant current source 5 connected in parallel to the optical modulator 2 for drawing out the photo-current generated in the optical modulator 2 by absorption of light emitted from a semiconductor laser. The modulating circuit can perform light intensity modulation with low wavelength chirping using a driver DC-coupled to the optical modulator 2. The drawing out current is approximately equal to or more than an average of photo-current which is generated in the optical modulator 2 by light absorption at the time of modulation.

Modulating circuit for semiconductor optical modulator

A low-dust dental alginate impression material composition is disclosed, comprising an alginate, a gelation reaction agent, a gelation regulator, and a filler as major components, which further comprises sepiolite and/or a tetrafluoroethylene resin having a true specific gravity of from 2.0 to 3.0. The low-dust dental alginate impression material composition of the present invention does not influence various capacities of the alginate impression material itself at all, is reduced in the generation of dust, and is superior in the storage stability.

Low-dust dental alginate impression material composition

In an optical transmitter and receiver device, a transmitter receives a transmitting data signal and drives a laser diode to make the laser diode emit an optical data signal representative of the transmitting data signal. The laser diode simultaneously emits a backward optical leakage signal. A photodiode is disposed at a rear side of the laser diode and detects the backward optical leakage signal as an optical monitoring signal to produce an electric monitoring signal. The transmitter receives the electrical monitoring signal to control an output power of the laser diode at a stabilized level. When the transmitter receives no transmitting data signal, the laser diode functions as an optical amplifier for an incoming optical data signal thereto and delivers an amplified optical data signal to the photodiode. The photodiode converts the amplified optical data signal to an electrical reception signal. A receiver receives and decides the electrical reception signal to produce a received data signal representative of the incoming optical data signal. Thus, the laser diode and the photodiode can be formed in a single optical module so that the optical transmitter and receiver can be reduced in size and cost.

Optical transmitter and receiver device with a single optical module

In a photoelectric converter module, a chip carrier which carries a photoelectric converter chip on a side surface thereof is fixed on a metal base of the module via a metal member by means of welding, and the photoelectric converter chip is connected electrically with a pre-amplifier via a conductor pattern provided on a surface of the chip carrier and a bonding wire, so that parasitic capacities generated between the photoelectric converter chip and the pre-amplifier are considerably reduced, and the chip carrier is fixed firmly without causing deviation of an optical axis between the photoelectric converter chip and optical systems including a lens.

Photoelectric converter module

In an optical isolator device using a Faraday rotator for permitting a forward light beam to pass therethrough but for preventing a reverse light beam from passing therethrough, two Faraday rotators are used in a cascade-connection in order to improve the temperature characteristic of the isolation over a wide temperature range. One of two Faraday rotators is prepared to have the Faraday rotation angle of 45.degree. for a wavelength shorter than the intended wavelength .lambda..sub.0, while the other having the Faraday rotation angle of 45.degree. for a wavelength longer than .lambda..sub.0. A polarizer and an analyzer are disposed on opposite ends of one of the rotators at a rear stage and prevent the reverse light beam from passing therethrough. Another polarizer and another analyzer can further be disposed at opposite ends of the other front stage rotator so that two isolators are arranged in a cascade-connection. The rotation angular deviation of the light beam caused at the front stage rotator by the temperature variation is cancelled by the rotation angular deviation caused at the rear stage rotator by the same temperature variation.

Growing community of inventors

Tokyo, Japan

Nobutaka Watanabe