Sony Corporation

Sony Group Corporation

Toshihiko Masuda

Kazunobu Ohkuri

Hiroshi Yoshioka

Shinpei Kondo

Hideyuki Taguchi

Hiroki Matsuoka

Yusuke Yamamoto

Takashi Kanai

Masaaki Ueki

Arihiro Moroboshi

Nobuyuki Yasuda

Takashi Shima

Takashi Takano

Massaaki Ueki

Takahiro Noda

Manabu Yamanaka

Takuro Akiyama

A display apparatus according to an embodiment of the present disclosure includes a thin plate-shaped display cell that displays image and a plurality of exciters disposed on a back surface of the display cell and causing the display cell to vibrate. The plurality of exciters is such configured that the plurality of exciters is regarded as one exciter when the plurality of exciters generates vibration in the display cell.

Display apparatus

A flat panel speaker according to an embodiment of the disclosure includes a flat panel and a plurality of vibrators that are disposed on a back surface of the flat panel. The plurality of vibrators are disposed to avoid a location that most easily vibrates in an entire range of audio frequencies when vibration is generated in the flat panel by the plurality of vibrators. A large stationary wave with respect to the flat panel therefore does not easily occur.

Flat panel speaker and display unit

A signal amplification apparatus which supplies an input signal to a signal processing section to perform signal processing on the input signal, amplifies a power supply voltage supplied from a power source section in accordance with the processed signal, and outputs the amplified power supply voltage. The apparatus includes output decrease prediction means for predicting decrease of the output signal on the basis of an amplitude of the input signal; power supply voltage correction signal generation means for generating a power supply voltage correction signal for correcting the power supply voltage of the power source section on the basis of the predicted decrease of the output signal; and feedforward control means for performing feedforward control of the power supply voltage of the power source section by using the power supply voltage correction signal.

Signal amplification apparatus and signal amplification method

A digital amplifier apparatus includes a gain-adjusting section operable to adjust a gain of a digital audio signal; a dither-superposing section operable to superpose a predetermined dither on the digital audio signal; a pulse-width-modulated signal generating section operable to generate a pulse-width-modulated signal corresponding to the digital audio signal; an amplifying section operable to cause a switching element to perform a switching operation in accordance with the pulse-width-modulated signal; a pulse-width changing section operable to change a ratio between a 'high' state and a 'low' state of the pulse-width modulated signal; a synchronizing section operable to synchronize the pulse-width modulated signal with a reset signal that resets the digital audio signal; and a control section operable to perform a resetting operation by setting the gain of the digital audio signal to a zero level upon receiving the reset signal, stopping the superposing of the dither to thereby generate the pulse-width modulated signal, and setting the pulse-width modulated signal to the &#x201c;low&#x201d; state by using the pulse-width modulated signal synchronized with the reset signal, thereby causing the switching element to stop performing the switching operation.

Digital amplifier apparatus and method of resetting a digital amplifier apparatus

A digital amplifier apparatus includes a gain-adjusting section operable to adjust a gain of a digital audio signal; a dither-superposing section operable to superpose a predetermined dither on the digital audio signal; a pulse-width-modulated signal generating section operable to generate a pulse-width-modulated signal corresponding to the digital audio signal; an amplifying section operable to cause a switching element to perform a switching operation in accordance with the pulse-width-modulated signal; a pulse-width changing section operable to change a ratio between a 'high' state and a 'low' state of the pulse-width modulated signal; and a control section operable to perform a muting process by causing the gain-adjusting section to set the gain of the digital audio signal to a zero level, the dither-superposing section to stop superposing the dither, and the pulse-width changing section to change, step by step, the ratio between the &#x201c;high&#x201d; state and the &#x201c;low&#x201d; state of the pulse-width modulated signal toward the &#x201c;low&#x201d; state upon receipt of a predetermined muting signal for muting the digital audio signal, thereby maintaining the &#x201c;low&#x201d; state and stopping the switching operation performed in accordance with the pulse-width modulated signal.

Digital amplifier apparatus and method of muting digital amplifier apparatus

A power amplifier apparatus includes a dither superimposing unit superimposing DC dither on a digital signal; a switching signal generating unit converting the digital signal on which the DC dither is superimposed by the dither superimposing unit to a pair of drive pulses on high and low sides having opposite levels; and a cancel signal generating unit generating a cancel signal to cancel a DC component caused by the DC dither by changing a ratio of pulse widths of the drive pulses on the high and low sides generated by the switching signal generating unit.

Power amplifier apparatus and DC component removing method

A D/A converter in which distortion caused by PWM is favorably removed even if a sampling frequency is low relative to a signal frequency is provided. The D/A converter includes a pulse-width-modulated-signal outputting circuit for outputting a pulse-width-modulated signal having a pulse width in accordance with a digital value of an input digital signal. A distortion-correcting-component generating circuit () for generating from the input digital signal at least a correcting component corresponding to a distortion component generated in the pulse-width-modulated-signal outputting circuit; a subtractor circuit () disposed at an upstream of the pulse-width-modulated-signal outputting circuit, for subtracting the correcting component generated by the distortion-correcting-component generating circuit from the input digital signal; and a phase correcting circuit () for correcting phase characteristics of the input digital signal so that the distortion component and the correcting component have a phase difference such that these components have opposite phases in the pulse-width-modulated-signal outputting circuit; are provided.

D/A converter and output amplifying circuit

In an audio amplifier having a D-class power amplifier, a noise upon muting is suppressed. A sampling rate converter circuit for sampling rate converting a digital audio signal into a digital audio signal, and a &#x394;&#x3a3; modulation circuit for re-quantizing the digital audio signal into a bit-reduced digital audio signal are provided. Further, a PWM modulation circuit for converting the digital audio signal into a PWM signal, and a D-class power amplifier to which the PWM signal are supplied. Still further, a dither signal forming circuit for superimposing a dither signal SDI on the digital audio signal, and a forming circuit for forming a muting signal SDET are provided. Upon muting, an input side of the sampling rate converter circuit is stopped by the muting signal SDET.

Audio amplifier

A class D power amplifier () switches a power supply voltage Vat high-speed in response to an input digital audio signal Pto power-amplify the digital audio signal P, and supplies a speaker () with the amplified signal. In the case of being incorporated in an AM receiver formed integrally with an AM tuner () for receiving AM broadcasts, the class D power amplifier () can reduces influence of reception interference with respect to the AM tuner (). As a result, it is possible to provide a power amplifier that can suppress unnecessary radiation to reduce reception interference with respect to the tuner, not by changing a carrier frequency, but by controlling the drive signal generation systems.

Power amplification device

A power amplifier for reducing emission generated at the edges of output voltages. A pair of PWM modulation circuits () and () to which an input signal is sent; a pair of push-pull circuits () and (); and drive circuits () and () for sending the outputs of the PWM modulation circuits () and () as drive signals to the push-pull circuits () and () are provided. A speaker () is connected between the output end of the push-pull circuit () and the output end of the push-pull circuit (). The drive circuits () and () are switched at intervals equal to the cycle period of pulse modulation signals such that the drive signals sent to the push-pull circuits () and () are not changed at the end points of each cycle period of the pulse modulation signals.

Power amplifier

A digital power amplifier includes a pulse width modulator for converting an input signal into a pulse width modulated signal according to a signal level of the input signal; an output stage, switching thereof being controlled by the pulse width modulated signal generated by the pulse width modulator; a pulse width modulation ratio detector for detecting a pulse width modulation ratio of the pulse width modulated signal generated by the pulse width modulator; and a control unit for disabling the switching operation of the output stage. The control unit disables the switching operation of the output stage when the pulse width modulation ratio detector detects that the pulse width modulation ratio is 50%.

Digital power amplifier and digital/analog converter

A signal amplifier apparatus adapted for carrying out delta-sigma modulation of an input signal to carry out pulse width modulation (PWM) of that signal, to obtain a PWM signal, and to amplify this PWM signal so that a signal of a predetermined magnitude is obtained, wherein the signal amplifier apparatus includes a correction circuit for correcting an output of a quantizer provided in a delta-sigma modulation device. The correction circuit is installed in a feedback path with respect to the input side from the quantizer or immediately before a pulse width modulator to thereby correct distortion taking place in the amplifier. In addition, the signal amplifier apparatus invention compares PWM signals at the input and the output of the amplifier to correct the output of the quantizer that is provided in the delta-sigma modulation device, so as to cancel distortion taking place in the amplifier in accordance with respective rising time difference and falling time difference to thereby correct distortion.

Delta-sigma modulation apparatus and signal amplification apparatus

A power amplifier circuit includes a pair of PWM circuits, to which an input signal is supplied, a pair of push-pull circuits, and drive circuits for supplying the outputs of the PWM circuits to the push-pull circuits as drive signals. A speaker is arranged between the output end of one push-pull circuit and the output end of the other push-pull circuit. The drive circuits alternately drive the respective push-pull circuits every cycle time of a PWM signal. The circuit can suppress radiation caused by the variation in output voltages.

A digital power amplifier including a switching control device for generating a first switching control signal and a second switching control signal which results from inverting the first switching control signal at an equal timing based upon an inputted audio signal, wherein the first and second switching control signals generated from the switching control device are respectively supplied to control terminals of first and second switching devices so that the first and second switching devices are driven in a push-pull manner to produce an audio signal amplified when the power source is switched. Output characteristics are prevented from being deteriorated by noise from the power source by canceling out radiation of the signals generated from the two switching devices and deterioration of outputted audio characteristics due to noise from the power source is prevented.

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Tokyo, Japan

Toshihiko Masuda