Sony Corporation

Takashi Kanai

Toshihiko Masuda

Kaneaki Fujishita

Kenji Nakano

Hiroshi Masuda

Shuichi Nagano

Kazuki Sakai

Masataka Yoritate

Minoru Inayama

Massaaki Ueki

An acoustic apparatus which outputs test signals from a plurality of speakers configuring a multichannel reproduction system and adjusts acoustic characteristics by picking up response signals from the speakers using a microphone, includes a test signal storage unit storing test signals output from the speakers; a response signal storage unit storing response signals from the speakers picked up by the microphone; a parameter calculation unit calculating acoustic adjustment parameters including at least a polarity reversal parameter and a phase filter parameter based on the response signals from the speakers stored in the response signal storage unit; and an acoustic adjustment parameter storage unit storing the acoustic adjustment parameters calculated by the parameter calculation unit. The parameter calculation unit calculates the polarity reversal parameter using a low-pass component of the response signals.

Acoustic apparatus, acoustic adjustment method and program

A sound-field production apparatus includes a direct-sound-generating unit for generating a direct sound from a sound signal supplied to the direct-sound-generating unit and a reflected-sound-generating unit for generating a sound serving as a substitute for a sound obtained as a result of reflection of the direct sound at a level lower than the direct sound with a timing lagging behind the direct sound from the sound signal supplied to the reflected-sound generating unit. The sound-field production apparatus makes it possible to reproduce an impressive sound field that gives a better feeling of presence on the scene as a sound field in a movie theater or the like does by creating a sound-field space having an effect of sound-image broadening.

Sound field production apparatus

A recording and/or reproducing apparatus for a disc-shaped recording medium which includes an optical head, a motor driven table for rotating the disc-shaped recording medium, a slider for moving the optical head relative to the motor driven table in a radial direction of the disc-shaped recording medium, an error signal generator for generating an error signal exhibiting the amount of the relative shifting of a spot of a light beam irradiated from the optical head on the disc-shaped recording medium with respect to a track on the disc-shaped recording medium, and a controller which detects a peak value and a trough value of the error signal supplied from the error signal generator and compares the difference between the detected peak value and the detected trough value with a reference threshold value to generate a drive signal for the slider on the basis of the comparison, wherein the drive signal from the controller is supplied to the slider to shift the optical head relative to the motor driven table in the radial direction of the disc-shaped recording medium to correct for eccentricity of the disc-shaped recording medium.

Disc eccentricity measuring apparatus and method thereof and apparatus for recording and/or reproducing disc-shaped recording medium

A sound reproducing system in which virtual image orientation processing of audio signals for at least two rear speakers disposed in directions from a listener close to the right-back direction from the listener is performed by a virtual sound orientation processor so that the listener can have a sound image at a position different from each of real speaker positions at which the rear speakers are placed, and/or so that the listener is unconscious that sounds are radiated from the rear speakers placed at real speaker positions. This virtual image orientation processing is performed according to acoustic transfer coefficients of transfer of sounds from the rear speakers to the listener's ears when the rear speakers are placed at virtual speaker positions different from the real speaker positions.

Method of reproducing sound

A pair of equilibrium output signals P(+) and P(-) from a 1-bit D/A converter IC, which is made up of an oversampling filter, noise shaper and a pulse converter, are supplied to a pair of field effect transistors connected in a common drain configuration. A constant current I.sub.0 is supplied to the common drain from a constant current source and at least one of the source output currents is converted by an output circuit into a voltage. In this manner, a 1-bit D/A converted output signal freed of fluctuations of the power source is provided at an output terminal.

Digital-to-analog converter

A signal input selecting circuit comprises a plurality of signal input terminals, a first switch device for selecting one of signal electrodes of the signal input terminals to be connected with a signal processing block, a second switch device for selecting one of reference electrodes of the signal input terminals to be connected with a reference potential point, a third switch device for connecting the second switch device with a current supplying portion, and a voltage detector for detecting a voltage corresponding to an impedance of the second switch device. When the voltage detected by the voltage detector has a level thereof less than a predetermined level under a condition in which the second switch device is in operation to connect the reference electrode of a selected one of the signal input terminals with the reference potential point and the third switch device is in operation to connect the second switch device with the current supplying portion, the third switch device is turned to disconnect the switch device from the current supplying portion and the first switch device is caused to connect the signal electrode of the selected one of the signal input terminals with the signal processing block.

Signal input selecting circuits

A PWM digital-to-analog converter is disclosed in which a value representing a differential between a first pulse width modulated waveform based upon input digital data and a second pulse width modulated waveform representing a 2's complement version of the input digital data is produced by a differential amplifier and high frequency components thereof are attenuated to produce an analog output signal and with an improved distortion factor.

Growing community of inventors

Chiba, Japan

Takashi Kanai