Sony Corporation

Hitachi, Ltd.

Alaxala Networks Corporation

Tooru Sasaki

Akira Kimura

Kohei Asada

Takayuki Mizuuchi

Masashi Ohkubo

Masayuki Inoue

Kunikazu Ohnishi

Motoyuki Suzuki

Yoshio Suzuki

Makoto Miyamoto

Nobuo Kobayashi

Yukio Fukui

Masaaki Kurebayashi

Yasuo Kitada

Kaoru Gyotoku

Junji Nakajima

Satoshi Shimada

Yasushi Katsumata

Shuuji Kameno

Hisamitsu Tanaka

Manabu Sawa

A simple configuration for cooling comprises a front-back air supply and exhaust system. A first circuit board is located in front of a relay circuit board. A cooling unit and a second circuit board are placed behind the relay circuit board in a chassis. A first air passage allows intake air through an intake hole in a front side of the first circuit board unit to pass through the first circuit board and then through an opening in the relay circuit board to the cooling unit. A second air passage allows intake air through an intake hole in a front face of the chassis to pass through a lateral side of the first circuit board and then through a vent hole in a partition provided at the lateral side of the first circuit board. The second circuit board is placed in the second air passage.

Network communication device

A speaker apparatus in which the acoustic sound is radiated by flexural oscillations of a diaphragm in the form of a panel having a substantially flat surface. The speaker apparatus includes a panel-shaped diaphragm the outer rim of which can be oscillated substantially freely at least in the direction along the diaphragm thickness and at least one driver unit constituting an oscillation source secured to the diaphragm surface for imparting oscillations to the diaphragm. The diaphragm is set into flexural oscillations by oscillations applied from the driver unit driven on the basis of the playback input signal. By flexurally oscillating the diaphragm to radiate the acoustic sound, optimum frequency response characteristics can be obtained over a wide frequency range from the low to high frequency range. Moreover, the acoustic sound of optimum sound quality may be radiated in a state of minimum sound pressure level fluctuations over a frequency range from the low to high frequency range.

Speaker apparatus and electronic apparatus having speaker apparatus enclosed therein

Speaker apparatus and electronic apparatus having a speaker apparatus enclosed therein

A noise reducing microphone apparatus having an adaptive noise canceller which has a primary input and a reference input and in which the reference input is subtracted from the primary input through an adaptive filter and the adaptive filter is adaptively controlled by an output signal resulted from the subtraction, comprises. The apparatus includes a pair of microphone units disposed in proximate locations; and subtracting means for performing subtraction of outputs from the pair of microphone units. An output from one of the microphone units is supplied as the primary input of the adaptive noise canceller. A differential output from the subtracting means is supplied as the reference input of the adaptive noise canceller.

Noise reducing microphone apparatus

A masking type light control layer for decreasing its reflection factor in a high-temperature region is formed on phase pits of an optical disc, and the phase pit depth is set to a predetermined value. A light spot for reproduction is shaped to an elliptical form and two sub-flux beams on the optical disc are spaced by 5/4 track pitch from a principal flux beam in the radial direction of the optical disc. The kind of optical disc is discriminated and reproduction laser power and characteristics of an equalizer circuit are switched in accordance with the type of an optical disc. Through this, a stable servo signal detection can be ensured and repetitive reproduction characteristics can be improved.

Optical disc with phase pits and a reproducing apparatus for data

A 2-laser optical head in which the number of optical parts is small and an arrangement is also simple and a whole optical system can be miniaturized. As a construction to realize the 2-laser optical head, there is a construction in a 2-laser optical head comprising at least: semiconductor laser devices for rewriting and reproducing; a beam splitter for transmitting a laser beam emitted from the reproducing semiconductor laser device and for reflecting a laser beam emitted from the rewriting semiconductor laser device; an objective lens for converging the laser beams and irradiating onto a recording surface of a magneto-optic disk, thereby forming a spot for reproduction and a spot for rewriting; a detection optical system for detecting a reflected light from the recording surface of the spot; and a detection optical system for detecting a reflected light from the recording surface of the spot, wherein a dichroism beam splitter is arranged in a manner such that the angles between normal vectors of incident surfaces and incident optical axes and are equal to 45.degree., and the occurrence of a phase difference which causes a deterioration of a deflecting state is corrected by a beam splitter.

2-laser optical head and recording/reproducing apparatus

A microphone apparatus having a first microphone for picking up a desired sound and a second microphone with directionality in which sensitivity is low to the desired sound arrival direction. A sound signal from the second microphone is supplied to a subtracting circuit through an adaptive filter. The subtracting circuit subtracts an output signal of the adaptive filter from the sound signal coming from the first microphone. A circuit is provided to adjust the adaptive filter so that the output power of the subtracting circuit is minimized. The setup implements a microphone system which is compact in size and easily provides desired directionality.

Microphone apparatus

A microphone apparatus having a microphone for producing a desired audio signal, includes an adaptive signal processing section which is supplied with a reference signal based on a vibration detected signal from a vibration detecting circuit in response to a vibration of a vibration generating source whose vibration is picked up by the microphone and becomes an unnecessary noise signal, or in response to a control signal for controlling a drive source of a driving unit of a recording apparatus for recording an output signal from the microphone and which reduces a noise signal contained in the audio signal.

This invention is concerned with a device for reducing the external noise reaching the ear in extremely noisy places such as in the vehicle or construction sites. According to the present invention, the external noise in picked up by a microphone provided in the vicinity of an electro-acoustic transducer element, such as a headphone unit, provided in the vicinity of the wearer's ear, and the noise signal converted in this manner into electrical signals is produced as the acoustic signal by the electro-acoustic transducer element. The transfer characteristics and controlled in such a manner that the produced noise signal prove to be an acoustic signal which is of the same frequency spectrum and opposite in phase with respect to the external noise reaching the wearer's acoustic meatus from outside to reduce the external noise reaching the acoustic meatus.

Noise reducing device

The present invention is concerned with a receiver device for converting electrical signal from a headphone, a telephone receiver or the like into acoustic signals. More particularly, it relates to a noise reducing receiver device in which acoustic signals in the vicinity of an electro-acoustic transducer element are converted by a microphone into electrical signals and negatively fed back to an amplifier circuit which is adapted for amplifying input electrical signals and supplying the amplified signals to the electro-acoustic transducer element. In the noise reducing receiver device, the input electrical signals are amplified by the amplifier circuit and converted by the electro-acoustic transducer element into output acoustic signals. A microphone is arranged in the vicinity of the electro-acoustic transducer element and adapted for converting the output acoustic signals and external noise into electrical signals, which are negatively fed back to the amplifier circuit via a feedback circuit. The output acoustic signals may be heard at a desired noise reduction level by adjusting the transfer function H of the electro-acoustic transducer element, the transfer function A of the amplifier circuit, the transfer function M of the microphone and the transfer function .beta. of the feedback circuit within a range determined by .vertline.AHM.beta..vertline.&gt;&gt;1.

Noise reducing receiver device

An apparatus and method for producing an output signal representing a sound pressure at a predetermined position wherein a first microphone is provided for producing a first output signal representing a sound pressure P.sub.0 at a first position; a second microphone is provided for producing a second output signal representing a sound pressure P.sub.1 at a second position; and a signal processing circuit is provided for producing the output signal based upon the first output signal and the second output signal; wherein the signal processing circuit is operative to produce the output signal proportional to: (i) a power function of the second output signal based on an exponent m corresponding to a distance between the first microphone and the predetermined position, multiplied by (ii) a power function of the first output signal based on an exponent representing a value obtained by subtracting at least the exponent m of the power function of the second output signal from 1.

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Tokyo, Japan

Tooru Sasaki