PURPOSE:To prevent a band-pass filter from being warped and to improve C/N characteristics by specifying the rate of the thickness of a low refractive index film to that of a high refractive index film. CONSTITUTION:A band-pass filter for separating and synthesizing two wavelengths is constituted of a dielectric multilayer film obtained by laminating the low refractive index films 34 and the high refractive index films 33 alternately and the rate dL/dH of the film thickness dL of each low refractive index film 34 to the film thickness dH of each high refractive index film is set up to 1-2. Namely, stress is influenced by the film thickness and it can be reduced in proportion to the reduction of the rate dL/dH. Thereby, the setting of the rate dL/dH to 1-2 makes it possible to reduce the stress sufficiently and include a phase different within + or -10 deg. to be an allowable range of a phase difference as a band-pass filter. Consequently, C/N deterioration of a magneto-optical disk signal due to the generation of a phase difference in S and P polarized light beams can be suppressed, a wave front aberration generated by stress can be reduced, a wavelength separating/synthesizing function can be prevented from being deteriorated, and the generation of defocusing can be prevented.

Band-pass filter

PURPOSE:To enhance abrasion resistance by dissolving a phthalocyanine derivative in sulfuric acid of >=98% purity, filling a porous insulating layer with this solution, precipitating the alpha-type phthalocyanine crystals from the solution, and regulating the crystal forms. CONSTITUTION:The electric charge generating layer is formed by dissolving the phthalocyanine derivative comparatively high in solubility in sulfuric acid perfectly in the sulfuric acid of >=98% purity, filling the pores of the porous insulating layer with this solution, precipitating the crystals of the phthalocyanine by hydrolytic treatment to convert the phthalocyanine in the solution almost not exhibiting photoconductivity into a photoconductive alpha-type phthalocyanine photoconductive crystals, and further regulating the crystal form by reacting them with a solvent to restore the initial characteristics of the phthalocyanine before dissolution, thus permitting the obtained photosensitive body to be superior in spectral sensitivity characteristics due to the phthalocyanine derivative, and yet to maintain high abrasion resistance due to the porous insulating layer.

Manufacture of electrophotographic sensitive body

There is provided a wind power installation comprising a synchronous generator which has a generator stator and a generator rotor for producing electric energy. The wind power installation further has a fluid cooling system for cooling the generator rotor.

Wind energy installation having a synchronous generator, and slowly rotating synchronous generator

Non-polarized thin film edge filter and optical fiber communication system used therewith

Disclosed is a stereo RF modulating system which converts stereo information along with image information to RF signals in an image recording/reproducing system. Conventional RF modulators can output mono audio information only and thus cannot provide viewers with high fidelity sound. Accordingly, the stereo RF modulating system comprising an audio matrix means, a pilot signal source, a first mixer, a RF carrier oscillator, a first and second local oscillators, a video modulator, first and second modulators, a second mixer, a first switching device, and a second switching device, converts stereo information along with image information to RF signals, and thus provides high fidelity sound.

Stereo radio frequency modulating system

PURPOSE:To mount a composite varactor diode with high density by combining two or more of varactor diodes having different voltage-to-capacitance characteristics and receiving them in one package. CONSTITUTION:Varactor diodes D1 and D4, D2 and D5, D3 and D6 for a tuner for receiving a CATV are constituted as a composite diode in which they are each combined and received in one package. The diodes D1, D2 and D3 must have common capacitance change characteristics, and the diodes D4, D5 and D6 must mutually have common capacitance change characteristics. The capacitance change characteristics of the diodes D1-D3 and those of the diodes D4-D6 must be made differ from the viewpoint of circuit selectivity, etc.

Composite varactor diode

PURPOSE:To use a UHF RF converter for a video disk and a tape recorder, by making a part of the RF converter into IC construction, and thus reducing its size and improving its reliability. CONSTITUTION:A DC regenerating circuit 3 which constitutes part of an RF converter for UHF and regenerates a DC component in a video signal, a DC offset voltage generating circuit 14 which generates an optional DC offset voltage for a DC potential regenerated by the circuit 3, and a polarity inverting circuit 15 which inverts the polarity of the offset voltage are made into IC construction in one substrate. In the substrate, an audio subcarrier oscillating circuit 4 which generates the audio subcarrier of a TV signal, a frequency modulating circuit 16 which imposes frequency modulation on the carrier from the circuit 4 by an audio signal, and an amplitude modulating circuit 17 which imposes amplitude modulation on the carrier are further integrated. This substrate is provided with changeover switch parts 18, 19a, and 19b, which are changed according to modulation polarities and modulation systems to allow the converter to be used for PAL and SECAM, obtaining a small-sized, high-reliability converter.

Rf converter for uhf

PURPOSE:To improve the attenuating performance in a low frequency region when a power supply is on, by providing a high pass filter to at least one of the input and output terminal sides CONSTITUTION:A switching transistor 6 is turned off when a power supply is turned off during which the power supply voltage is not applied to a switch control terminal A low pass filter is formed with inductance elements 1 and 2 and a capacitor 5 At the same time, a high pass filter consisting of a capacitor 13 and an inductance element 14 is connected to the side of an input terminal 3 Then the matching of impedance is set properly between these high and low pass filters Thus the attenuating performance is improved in a low frequency region and when the power supply is turned on without deteriorating the inserting loss when the power supply is turned off The same effect is obtained by providing a high pass filter at the side of an output terminal 4

Switching device of high frequency signal

PURPOSE:A TV tuner which can receive a cable transmission signal, including a CATV signal, as well as an aerial signal with a simple circuit constitution using no converter.

Multiichannel reception tuner

PURPOSE:To decrease easily a spurious radiation component at an antenna terminal by using a balanced type diode modulator to a mixing circuit converting a received UHF signal into a desired intermediate frequency. CONSTITUTION:When a single balanced type diode modulator is used for the mixing circuit 5c and the balancing condition is realized completely to a balun 16 and two mixing diodes 14, 15, a local oscillating signal inputted from a local oscillating circuit 6c to a coupling line 17 is not appeared theoretically at a terminal 23 being output of the balanced modulator. It is not required to realize the complete balancing condition actually, it is sufficiently by having only to take the attenuation of a local oscillating signal valve of 20dB, and in order to realize the balancing degree like this, it is attained with almost no adjustment by applying pairing to the diodes.

Nakamura Jiyouji

Papers

Composite varactor diode

Rf converter for uhf

Switching device of high frequency signal

Multiichannel reception tuner

Mixing circuit of television tuner